Door latch mechanism



June 11, 1940. K. M. SLETTEN 2,203,845

DOOR LATCH MECHANISM Filed Sept. 30, 1937 V 40 KHz/ml]; JVL. Sfktb m/ INVENTOR.

BY ma O A T YS.

Patented June 11,1940

juni'rsoy STATES PATENT OFFICE noon LATCH MECHANISM Kermit M. Sle t ten, .Willmar, Minn. Application September 30, 1937, Serial No. 166,523

Claims. (01. 292-336) My invention relates. to an improvement in a position, so thatthe. rotary latch is released when door latch mechanism of a type particularly closed position of the door is attained. As the designed for. use on vehicle doors and the like. trigger mechanism is much more easily operated It has been common practice in vehicle conthan is the bolt of the usual type of lock, this 5 struction t provide door latches having a recipconstruction enables thedoor to be closed much 5 rocable latch member having a cam shaped end more easily than the constructions where the which engages a keeper on the door frame to hold ordinary type of lock is emp y d thedoor in closed position. In view of the fact It is a purpose of the present invention to prothat the frame of a vehicleoften springs out of vide a latch in the. form of a rotary segment l0 proper position to a certain extent, deforming which is held in one extreme position bya pawl the body, the keepers of such latches are ordior dog, engaging in one of a series of notches in narily provided with a double latch so that the the rotatable member; The rotatable member is door will not come open until the latchbolt has urged toward the other extreme position by means passed both portions of the keeper. This is to of a suitably positionedspring. The series of prevent the action of the vehicle in travelling over notches, engageable with the pawl or dog, ascer- 15 a bump from freeing the latch momentarily and tains that the cam remain in inoperative posipermitting the door to swingopen. .It is also to tion and will not rotate into keeper engaging 1 permit the door to be latched shut even though position when out of engagement with the keeper.

the body has sprung sufliciently sothat the door It is the purpose of the present invention to 30 cannot be closed tightly. i provide a latch bolt which is held in inoperative 2O It is a purpose of my invention to provide a position by means ofa trigger equipped with an latch mechanism which may be used upon veoperating cam. This cam is operated by engagehicles and which will be tightened by; jarring or I ment with the door frame and when the door vibration. Thus if thedoor is not entirely closed reaches proper position within the frame, the due to warping or deformation of the vehicle, the trigger mechanism releases the latch bolt and movement of the car will cause the latch to enpermits the same to engage the keeper. gage more tightly and to thus hold the door It is a further object of my invention to proclosed more securely. The present invention is vide a latch mechanism which is virtually enamodification of my priorconstruction disclosed tirely contained within the body 0f the (1001 and in application for Door latches, SerialNo. 153,123, which is provided merely with a small cam exfiled July 12, 1937. i tending from the door. Thus with my novel con- It is a purpose of my invention to provide a struction, it is virtually impossible to catch and latch the form of a. rotatable cam which may tear the clothes in the manner of the latch bolt pivot into position tolock the door to the frame. of the ordinarytype of lock. i e This cam is preferably a segment of a screw These and other objects and novel features of thread and is urged into door engaging position my invention will be more clearly and fully set by means of a suitable spring. The angle of the forth in the following specification and claims.

thread is :such that transverse force acting In the drawing forming a part of my specificaagainst the cam cannot rotate the cam so that tionn vibration of the vehicle can only act to tighten Figure l is a top plan view of my door latch in 40 the cam in the keeper. inoperative position.

It is a feature of my invention to provide a Figure 2 is a cross-sectional view on the line door latch construction in which the door may be 2--2 of Figure 1, illustrating the latch bolt. opened or closed with the least amount of re- Figure 3 is a View similar to Figure 2 illustratsistance. Where the usual type of reciprocable g t e latch bolt in a ent position. 45

bolt having a cam end is employed some force is Fi ure 4 is a ran v rse cross-sectional view usually required to force this bolt inwardly to o t y through the Ce e O t e Shaft hanpermit the door to latch properly. For this readieof the latch mechanism, illustrated in Figures son it hasbeen necessary to slam the vehicle door and i 5 onto close the same quickly. in order that the Figure 5 is a perspective view of the latch nlatch bolt be reciprocated inwardly to pass the mechanism.

keeper. It is a purpose of the present invention Figure 6 is a view of the spring which operates to provide a rotatable latch device which is held the vehicle handle andholds the handle normally from rotation by means of a suitable trigger in one position.- l which is released when the door reaches closed My latch mechanism A includes a handle it) of 55 not directly connected to thesleeve iii to operatethe usual type used on vehicles andthe like. The handle in is provided with an external portion ll of relatively large diameter, a shank E2, or portion of reduced diameter, and a'squared portion l3 at the end of the shank l2. The handle l extends through the side flange M of the latch frame l5 and extends through a sleeve I6. The shoulder I! formed by the reduction in diameter of the shank I2 from the external portion ll, bears against the side flange Id to properly position the. handle it with respect to the latch mechanism frame l5.

A segment 89 is formed integral with the sleeve It. This segment 'I 9 as best illustrated in Figure 1 of the drawing is a segment of a gear thread, or in any event the periphery of the segment or cam I9 is helical with respect to the handle H]. A gear segment 26 is also provided integral with the sleeve it for engagement with the segment 2i. The segment 2B is pivoted at 22 illustrated in Figure 2 of the drawing, and this segment is urged into one extreme positionby the spring 23. The spring 23 tends to rotate the cam or segment l9 into engagement with the keeper 24. Accordingly, a constant pressure is provided tending to rotate the cam l9 into position to close the door tightly.

I provide a trigger mechanism for holding the cam or segment 19 out of keeper engaging position. This mechanism comprises a pawl or dog 25 which engages in one of a series of parallel notches 265 in the peripheral edge of the cam or segment l9. When the dog 25 is in engagement with one of the notches 26, the cam I 9 is prevented from moving in the direction in which it is urged by the spring 23. 1

The dog or pawl 25 is mounted upon a transverse shaft 21 mounted between spaced bearings 29 and 30. The pawl or dog 25 is secured for rotation with the shaft 2? between the bearings 29 and 3!! and a downwardly extending arm 3| is also similarly mountedon this shaft 21. At the lower extremity 32 of the arm 3!, I provide a cam shaped element 33 which is engageable with the frame 34 of the vehicle B. In Figure l of the drawing, the cam 33 is illustrated in full lines while in dotted lines in this same view-is illustrated the cam 33 forced inwardly by the vehicle door frame 34 to release the bolt IS. A spring 35 is provided between the frame 15 of the latch mechanism and the arm 3|.

From the foregoing description it will beclear that if the cam. I9 is in the position illustrated in full lines in Figures 1, 2, and 5 of the drawing, and the door upon which. the latch is mounted is closed against the frame M of the vehicle B, the cam end 33 will be pivoted against tension of the spring 35 so that the arm 3! swings inwardly rotating the shaft 21 and pivoting the pawl or dog 25 to release the cam l9, whereupon this cam is free to pivot by action of the spring 23 into the closed position illustrated in dotted outline in Figure 1 and shown in Figure 3 of the drawing.

As was previously described, the handle i0 is this sleeve. The squared portion it of the handle ID is provided with a square bushingtt,

cular flange 42 on the end of the sleeve l6. Riotation of the handle It! can only occur when the handle is in normal position and the arm 31 is in the full line position illustrated in Figure 6. The arm 31 may only pivot in a clockwise direction from the position illustrated in full lines in Figure 6 to the position illustrated by dotted outline in this same figure. When the cam I9 is in the position illustrated in dotted outline in Figure 6 of the drawing, the latch bolt I9 cannot be operated by the handle ID, as this bolt is already in retracted position. However, when movement of the door containing the latch mechanism into engagement with the door frame 3 3 causes the cam 33 to release the pawl or dog 25, the cam I 9 rotates into the position illustrated in Figure 3 of the drawing, bringing the edge 43 into engagement with the operating surface 34 of the arm 31. When the handle I0 is then rotated to turn the shaft of Figure 6 in a clock-wise direction, the surface 44 of the arm 37 which rotates with the handle ID will engage the end 43 of the flange 42 and permit rotation of the sleeve l6 into the position illustrated in Figure 6. When the sleeve 42 reaches this position, the latch bolt H) or cam is removed from the keeper 24 and the door may be swung open. As the door is swung open, the cam 33 disengages from the doorframe and the pawl or dog 25 engages one of the notches 26 in the periphcry of the cam l9. As soon as the handle I0 is released the spring 39 rotates the handle in a counter-clock-wise direction, moving the, handle into normal position. This construction en ables the'handle of the door to remain in normal position at all times when it is not being used, whether the cam is in looking position or is in open position.

The cam segment is held in inoperative position by the pawl or dog and the cam trigger which operates this pawl or dog may be seen from an observation of the drawing. The latch bolt or cam is not released until the. door is virtually entirely closed and it may be seen that vibration tending to move the cam l9 will cause this cam to be moved more securely into engagement with the keeper, being urged. in this direction at all times by the spring 23.

The manner in which the lock is actuated by an operating handle on the inside of the door is not illustrated in the drawing. It is believed only necessary to point'out that the handle on the inside of the door operates the gear 2| pivoted at 22 in a manner well known in the art.

In accordance with the patent statutes. I have described the principles of construction of my door latch mechanism and while I have endeavored to set forth the best embodiment there'- of, I desire to have it understood that this is only illustrative of a means of carrying out my invention, and that obvious changes may be made within the scope of the following claims without departing from the spirit of my invention.

I claim:

1. A door lock comprising adoor handle, a sleeve on. said handle and rotatable with respect thereto, a latch cam on said sleeve, means for rotating said sleevein a direction to rotate said cam into locking position, said. handle remaining stationary, means on said handle engageable with said sleeve for'pivo-ting said sleeve out of. locking position, a series of notches in the periphery of saidcam, and trigger, means engage-' able in one of. said notches, saidztrigger meansl being operated by engagement with a door frame to disengage said notch to permit rotation of said bolt.

2. A door lock comprising a, handle, a sleeve rotatable on said handle, a locking cam on said sleeve, spring means urging said sleeve into locking position, a notch in the periphery of said cam, and trigger means engagealole in said notch to hold said cam from rotation, said trigger means including a dog engageable in said notch,

, a pivot extending parallelto said handle supporting said dog, and means engageable with a door frame to actuate said pivot.

3. A door lock comprising a door handle mechanism comprising a shank and a means urging said shank into one position; a sleeve on said shank, a cam on said sleeve, spring means urging said sleeve in one direction while said handle mechanism remains stationary, shoulder means forming a part of said handle mechanism a for rotating said sleeve in the opposite direction,

and trigger means for holding said cam in un- 1 locked position, said trigger means including a pivot, door frame engaging means for operating said pivot, and dog means operated by said pivot.

4. A door lock comprising a handle mechaj nism including a shank rotatable between two extreme positions, and a means urging said shank into one extreme position; a sleeve on said shank, means for rotating said sleeve in one direction while said handle remains stationary, a locking cam-0n said sleeve, means forming a part of saidhandle mechanism for rotating said sleeve in the opposite direction, a dog engageable with said cam, spring means urging said dog into engagement with said dam to hold said cam in unlocked position, adog supporting pivot, and cam means engageable with the door frame to rotate said pivot to swing said dog out of engagement with said cam to release said cam to move under spring tension into locking position.

5. A door lock comprising a handle mechas able with a door frame when the door is closed to release said trigger means.

KERMIT M. sLE'r'rEN. 

